This invention relates to a displacement sensor for use with robot end effectors in tactile operations, and more particularly to an optical displacement transducer having an improved design for directing the light flow in a desired direction.
In modern technologies, it is most important to use a robot which is capable of determining an object shape through contact. For this purpose, various types of displacement-type transducers have been used, such as electrical transducers, which use various instruments to measure displacement, force transducers, which use a pliable solid to vary a certain electrical current or optical displacement sensors, which measure the amount of light deflected from an object to determine its position. The last mentioned type can find its wide application in, for example, virtual reality systems for receiving the distance or shape information through touch, or the so-called tactile sensing.
Since the optical sensors use light to transmit information, they offer many advantages of electrical transducers, such as high sensitivity, versatility in design and high immunity to electromagnetic interference. Some of the optical displacement sensors use fiber optics to transmit and receive light reflected by an object. In fiber optic sensors, a light emitting diode is used to emit light which is reflected to a phototransistor.
Many other industries utilize optical displacement sensors for performing quality control operations, for example to compare the shape of a "master image" with the article being made; to detect the number of items passing through an assembly line, etc.
The tactile sensors use pairs of emitter/detector hands arranged in arrays of sensors which move in predetermined directions, either in three axial directions, six axial displacements, etc.
The present invention relates to a type of transducer which is used to measure physical contacts made by, for example, robotic hands, with the use of a light beam.